Questions tagged [mutablestateof]
The mutablestateof tag has no usage guidance.
mutablestateof
45
questions
11
votes
2
answers
3k
views
Why does mutableStateOf without remember work sometimes?
I've been playing with Jetpack Compose Desktop. I noticed something I really don't understand:
import androidx.compose.desktop.ui.tooling.preview.Preview
import androidx.compose.material.Button
import ...
- 1,344
8
votes
1
answer
5k
views
Jetpack Compose TextField not updating when typing a new character
I followed this document from the developer site.
I want to display the text in an OutlinedTextField from a user input, and have it survive configuration changes.
With the code below, when the user ...
- 580
6
votes
1
answer
4k
views
How to use null as default value - Compose mutableState
I have a need like on first time on UI load the mutableStateOf Boolean value must be null , instead of default value as true/false similar to regular boolean value in Kotlin as
var isBooleanValue: ...
- 175
3
votes
0
answers
494
views
Checkbox in Jetpack compose not updating with the state value
I am creating a list of data to be multi selected and also want to add functionality by adding "Select All" option to select/deselect all the items at once.
The issue I am facing is when ...
- 768
2
votes
2
answers
676
views
mutableStateOf holding the value after the recomposition without remember API in Jetpack Compose
Any time a state is updated a recomposition takes place.
but here, I haven't used the remember API, but after the recomposition also it's holding the value, is the mutableStateOf() will remember the ...
- 3,618
2
votes
1
answer
444
views
How SnapshotStateList detects that a change has occurred?
Suppose I have a SnapshotStateList for Student, and the definition of Student is:
data class Student<val id: Int, var name: String>
val students = mutableStateListOf(Student(0, "Aaron"...
- 1,430
2
votes
1
answer
3k
views
Can I update a list in StateFlow (and change Compose View) without manually generating a new one just to modify one value in the list?
I have a lazyColumn of todo item
data class TodoItem(val id: Int, val title: String, var urgent: Boolean = false)
class AppViewModel : ViewModel() {
private var todoList = mutableListOf(
...
- 57.1k
2
votes
1
answer
428
views
Android Jetpack Compose rememberSystemUiController() doesn't observe mutableStateOf()
I'm trying to achieve a hide/show functionality for status bar in an AbstractComposeView
class MyView @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr:...
- 653
2
votes
1
answer
211
views
How to properly use mutability in Jetpack Compose to update Text when a value in a companion object is changed? (Kotlin)
EXPLANATION:
I have a budget screen
the Home.kt class basics are here:
@Composable
fun Home(navController: NavController) {
var currentBalance = Budget.currentBalance
Column(
/* ... */...
- 23
1
vote
2
answers
1k
views
Boolean State in compose is changing before the variable I put after it get's assigned
So I have Two ViewModels in my Calculator App in which I all reference in my Compose NavGraph so I can use the same ViewModel instance. I set a Boolean State(historyCheck) in the first ViewModel and I ...
- 103
1
vote
2
answers
494
views
Updating item in a mutableStateList is not triggering recomposition in UI (LazyColumn)
I have been scratching my head over this problem.
I have a data class representing items that can be selected(or unselected).
data class FilterItem(
val name: String,
val isSelected: ...
- 51
1
vote
1
answer
238
views
MutableStateOf of mutableList not updating
Why my mutableStateOf of mutableList not updating?
val checkedList by remember {
mutableStateOf(MutableList(list.size) { false })
- 525
1
vote
1
answer
202
views
WearOS compose error: "java.lang.NoSuchMethodError: No static method mutableStateOf(J)Landroidx/compose/runtime/MutableLongState" [duplicate]
I wanted to start programming a wearOS app, so I just created an new project. But when I started the emulator to check if everything works, the default "hello world" application crashed and ...
- 31
1
vote
1
answer
1k
views
Compose UI not updating the state after updating the view model
I am trying to update a compose UI view based on the state changes in the view model, below is my code Initially i am making assigning and doing operation by the default value from view model to a ...
- 175
1
vote
0
answers
328
views
Compose Android - Update a Item from list without page refresh
I have a LazyColumn list which holds user Items and I have populated the list Item view no issue on that, in here say I need to update a view from the Item like updating the user profile picture ...
- 175
1
vote
0
answers
297
views
Android, Jetpack Compose - Composable function not getting refreshed
I am new to Android Jetpack compose.
All i want to do is to update data in UI when it gets from API.
Here is my Composable function:
@Composable
fun getCurrentWeather(lat : Double, long : Double, nc : ...
- 545
0
votes
1
answer
59
views
Jetpack Compose: Surface makes state is persisting without remember
im currently experiencing with jetpack compose states.
Check out this composable:
@Composable
fun CounterWithoutRemember(reset: MutableState<Boolean>) {
val count = mutableStateOf(0)
...
- 129
0
votes
1
answer
417
views
Jet Pack Compose Mutable List Updating With Mutable State list Problem
//declared in activity
val statebilledproducts = viewModel.listBilledProducts
//declared in viewmodel
class OrderViewModel : ViewModel() {
private val _listBilledProducts = mutableStateListOf<...
0
votes
2
answers
95
views
Why snapshotFlow is trigged with MutableState as property delegate?
I have a situation with the snapshotFlow recently when trying to observe changes from a MutableState. Here is the snippet
val searchQuery = mutableStateOf("")
snapshotFlow { searchQuery }....
- 177
0
votes
1
answer
36
views
How update state with copy function
My Ui state
data class LoginUiState(
val loginModel: LoginModel = LoginModel(),
) : UiState
My ViewModel
@HiltViewModel
class LoginViewModel @Inject constructor() : BaseViewModel<LoginUiState&...
0
votes
2
answers
118
views
How to use multiple mutableState in one compose screen
I have three api in ViewModel that are below.
API for UserList
API for DeviceList
API for EventList
All api have three state (Loading, Success, Error)
I have to show all three info on Dashboard.
...
- 99
0
votes
1
answer
91
views
Is passing mutablestate to composable function optimal?
Like this :
@Composable
fun TextEdit(textState: MutableState<String>) {
val text by textState
TextField(onValueChange = {
text = it
}, value = text)
}
Is it optimal for ...
- 81
0
votes
1
answer
48
views
printing mutableState parameters
I have a class Plan() that has the parameter "val changeNumber : MutableState<Double?>".
as in
Plan(
...
val changeNumber : MutableState<Double?>
...
){}
I want to display this ...
- 15
0
votes
1
answer
422
views
Variable not updated in compose
I have a class in Kotlin (Jetpack compose) with a variable title and an exoplayer that updates the title.
class Player{
var title by mutableStatOf("value")
....
title= "new value"
...
- 179
0
votes
4
answers
1k
views
Listen to changes in only particular object in a StateFlow of type List?
How to listen to only a particular element in the MutableStateFlow of type list? If we listen to the entire list, then all the Views that are listening to the list if changed would rebuild themselves ...
0
votes
1
answer
494
views
Text and Button Color not updating when MutableState object changes
For the below code, I'm trying to get the selectedColorsText to update whenever a user clicks on a button. The button background should then turn black and the text inside it white once selected. If ...
- 429
0
votes
1
answer
1k
views
Attempt to invoke interface method on a null object reference in kotlin
After implementing viewmodels to jetpack compose app when I running the app it's showing a error :-
Attempt to invoke interface method 'boolean java.util.Set.contains(java.lang.Object)' on a null ...
0
votes
0
answers
3
views
combining multiple mutablestates
just started picking up Compose MP and have been running into difficulty combining 2 sources of mutablestates to a new mutablestate or flow within a viewmodel.
per documentation https://developer....
- 17
0
votes
1
answer
22
views
Fragment which is not in foreground is not getting updated while observing a state object in activity scope viewModel
I am using Jetpack compose for my UI rendering. I have Fragment1 and Fragment2. I have a viewModel SharedViewModel which is defined in activity scope.
When I send an update from Fragment2 which is in ...
- 366
0
votes
0
answers
78
views
What is more efficient mutableStateOf or mutableStateFlow?
I would to like to use MutableStateFlow in Compose components.
var hasReadCode by remember { mutableStateOf(false) }
var hasReadCodeFlow = remember { MutableStateFlow(hasReadCode) }
I have ...
- 147
0
votes
0
answers
40
views
No virtual method Boolean call-mutableStateOf
Get the next error, when I try to create a properties variable in a actual fun
java.lang.NoSuchMethodError: No virtual method
Boolean$arg-2$call-$init$$arg-0$call-mutableStateOf$fun-$anonymous$$arg-0$...
- 5,050
0
votes
0
answers
18
views
Android: Testing ViewModel with coroutines and states
I have been trying to understand how testing of ViewModel work in Android. I have the following view model class:
@HiltViewModel
class AllLaunchesViewModel @Inject constructor(
private val ...
- 2,188
0
votes
1
answer
659
views
LazyColumn in jetpack compose does not recompose when list data changes, but forloop over data list works, I am not getting why and what is happening
I am developing a app using jetpack compose, and I am new to this UI framework,
I want to display the categories amountSpent property.
I am changing the amount spend in dialog and want to reflect the ...
0
votes
1
answer
231
views
What is the syntax to make a callback function variable mutable in Jetpack Compose?
I'm trying to make the following variable, selectedView, mutable so that I can set the current Composable View dynamically.
var selectedView :@Composable () -> Unit = { testView() }
I'm passing ...
- 1,735
0
votes
0
answers
14
views
assertHistorySize() for State or MutableState in Android Test
I am used to use awaitValue + assertHistorySize to test how much a LiveData has received and what it has got.
So I write the following code (only as an example):
val dataObserver = viewModel.data()....
- 1
0
votes
0
answers
34
views
Question about atomized modifications to SnapshotStateList
I am using SnapshotStateList to maintain a list of Elements to feed the compose UI.
When I add, remove, and replace elements to this list, they trigger my LazyColumn component to recompose. this all ...
- 1,430
0
votes
1
answer
64
views
UI not updating properly on first launch of app Android Compose
I have the following code in my HomePageViewModel:
private val _overallStitchCount: MutableStateFlow<Int> = MutableStateFlow(0)
val overallStitchCount: StateFlow<Int> = ...
- 276
0
votes
0
answers
39
views
UI not updating when viewmodel variable has changed jetpack compose
My variable is defined as follows in my view model:
private val _overallStitchCount: MutableStateFlow<Int> = MutableStateFlow(0)
val overallStitchCount: StateFlow<Int> = ...
- 276
0
votes
0
answers
82
views
MutableStateFlow does not emitting value changes
Case is,I'm scanning hardware with NFC and getting texts from it,it has some steps to receive texts.for example:
step 1 - starting scan,
step 2 - scan in progress,
step 3 - scan is almost finished,
...
0
votes
1
answer
422
views
mutableStateListOf not doing recomposition on replacing some element in the list with targetsdk 33 and kotlin 1.7.20
Recomposition will happen only when you change the list itself. mutableStateListOf can only notify about adding, removing, or replacing some element in the list.
Reference: Android Jetpack Compose ...
- 9,371
0
votes
2
answers
859
views
How to update UI with a viewModel for byte arrays and lists in Kotlin/Jetpack Compose?
So the problem I am facing is that when the viewModel data updates it doesn't seems to update the state of my bytearrays: ByteArray by (mutableStateOf) and mutableListOf()
When I change pages/come ...
- 15
0
votes
0
answers
118
views
Test that value contained in MutableState is updated correctly
I have a viewModel that looks like this
class PhotoViewModel(
private val getPhotoUseCase: GetPhotoUseCase
) : ViewModel() {
val photo: MutableState<PhotoItem?> =
mutableStateOf(...
- 1,438
0
votes
1
answer
85
views
Mutablestateof - State hoisting
What to do to manage one state in two functions? (openDialog)
How to transfer openDialog state from ProductDialog() to AppBar()?
I know I can make a separate class per state but I don't want to.
@...
- 3
0
votes
1
answer
2k
views
What is the proper way to update TextField string value after successfully loading data to pre-fill the TextField from database?
I am using Jetpack Compose, and it has occurred to me that I may be doing this incorrectly.
Suppose we have a screen that allows us to edit a form's data, which has been saved locally using Room. ...
- 23
0
votes
0
answers
217
views
MutableState value not getting updated in Observer block
I have a live data that I am observing in my fragment, in which I have to act on the result received from LiveData and update my MutableState which is used in a composable.
I am not able to figure out ...
- 2,164